Mass killers are not identical but there are specific personality traits that they tend to share. Paranoia, narcissism, and psychopathy are the most common that cluster together. Though many people have these traits and never commit violence, it’s an area of concern that indicates the need for careful screening by mental health clinicians.
Personality is the characteristic way we perceive, think, feel, and behave in the world. It’s stable over time and in a variety of settings and circumstances. Our personality causes us to interpret and interact with the world in specific and unique ways. Personality is the result of the complex intertwining of genetic and environmental factors.
A person with a paranoid personality disorder tends to look at the world through a suspicious lens. They often assume that others are out to get them or think negatively about them despite there being no objective evidence that this is happening. They typically ascribe malevolent motivations to others, often incorrectly.
Paranoid individuals often misperceive benign remarks as attacks. They consistently scan their environments for evidence that supports their suspicions and connect with others online who share their way of thinking. The more they are supported in their suspicions, the more paranoid they become.
Paranoid people tend to hold grudges and think about revenge.
People who are narcissistic have an exaggerated sense of self-importance. Others tend to describe them as arrogant.
They spend a great deal of time fantasizing about their superiority over other people. They tend to exaggerate their talents without commensurate achievements. They are preoccupied with fantasies of unlimited success, power, brilliance, attractiveness, and ideal love. They crave admiration and are quick to become angry when they don’t receive it.
Narcissistic people are entitled to special treatment and become angry when they don’t receive it. They don’t experience empathy for other people and are prone to envy others’ success. They also tend to hold grudges and may fantasize about revenge.
A person with psychopathy does not have empathy for others and is indifferent to their suffering. Their interactional style is transactional – they only care about people who can benefit them. A psychopathic person disregards others’ rights and tends to lie, con, or manipulate others for personal gain or pleasure.
Psychopathic people are often superficially charming and are masters of impression management. They often appear normal in superficial social interactions and know how to make others like and trust them. Sometimes they become successful in their careers though they have no concern about violating laws or the rights of others. They are capable of cruelty.
The psychopath lacks an internal moral compass and may engage in behavior that results in arrests. They are often prone to violence. People high in psychopathy tend to be impervious to fear and feel no guilt or remorse for their behavior.
When we understand risk factors, those in the helping professions are better able to target interventions in ways that will help guide individuals with these personality traits in ways that minimize potential dangerousness. The earlier treatment is started, the better.
My interview on Court TV on this topic
The book The Minds of Mass Killers: Understanding and Interrupting the Pathway to Violence
Personality Traits Common in Mass Killers
I very much appreciate how the succinct summaries highlight the overlapping characteristics and in sequence of their significance/prominence in each disorder. An interesting podcast might be discussion of prominent criminals with a Name That Personality Disorder theme. This is the kind of thing my family might have played at Thanksgiving and Christmas, between Settlers of Catan and contract bridge. ;-)